1. Field of the Invention
The present invention relates to a sector synchronous signal judgement and generation method for a disk reproducing apparatus and more to an improved sector synchronous signal judgement and generation method for a disk reproducing apparatus which is capable of preventing an erroneous recognition of a sector synchronous signal due to a noise or bit errors and generating a sector synchronous signal which was missed.
2. Description of the Conventional Art
Generally, a compact disk (CD) is widely used for a disk reproducing system as a reproducing medium. The CD uses only a frame synchronous signal which can be expressed in various forms (for example, 10000000000100000000001).
However, a sector synchronous signal for separating a sector exists in a digital video disk (DVD) system in addition to the frame synchronous signal. In the DVD system, the sector synchronous signal cannot be expressed as the frame synchronous signal as in the CD because the sector synchronous signal has various restrictions in a coding method, a signal offset of a low frequency band width, etc. Therefore, one synchronous signal is arranged in a head portion of each sector for separating the sectors after various kinds of synchronous signals are generated.
FIG. 1 is a view illustrating a synchronous signal used in a conventional digital video disk.
As shown therein, on the assumption that there is a "a" number of synchronous signals, each synchronous signal (SY0, . . . , SYa) including an the m-number of binary bits.
In addition, each synchronous signal (SY0, . . . , SYa) includes a bit X and a frame synchronous signal "frame sync". The bit X is formed of 0 and 1, and the frame synchronous signal is of a fixed type.
FIG. 2 is a view illustrating a conventional sector structure.
As shown therein, one synchronous signal SYxl among various synchronous signals is used as a synchronous signal of a first frame of the sector, and the other synchronous signals (SYx2, . . . , SYxn) are used as the synchronous signal of the remaining frames. Namely, when the synchronous signal SYx1 is detected, the thusly detected synchronous signal SYx1 becomes a sector synchronous signal.
However, when detecting the sector synchronous signal by using the above-described structure, the sector synchronous signal SYx1 may be lost due to noise or the like at the moment when the sector synchronous signal SYx1 is detected and is mistakenly judged as another signal, thereby causing a malfunction in the system and degrading the quality of a picture to be displayed.
Furthermore, since the CD judges the sector synchronous signal by using only the frame synchronous signal, it is impossible to properly match with the synchronous signal having various types as in the DVD, thereby increasing the possibility of the errors.